Dynamoelectric machines having high power densities almost universally utilize some means of liquid cooling of various conductors. In some cases, the conductors are hollow and a liquid coolant is flowed through the conductors for cooling purposes. This approach, while quite satisfactory, is generally limited to dynamoelectric machines which are physically large because of the inability to provide small hollow conductors through which a liquid coolant might flow without intolerable pressure drops.
Thus, in smaller dynamoelectric machines, conductors may be multi stranded, or they may have external shapes such that interstices exist between the strands of adjacent conductors which may be used to provide coolant flow passages. In the usual case, these conductors will be passed through the slot in, for example, a dynamoelectric machine stator and emerge from the ends thereof as end turns as is well known. Causing coolant flow through the slots of the stator to cool the conductor within the slot is readily accomplished and has been for many years. However, where the coolant emerges from the slots at the end faces of the stator, its velocity may be slowed so that even though it continues to contact the end turns, heat exchange drops and adequate cooling of the end turns cannot be easily accomplished.
Conventionally, to overcome this difficulty, the end turns of the stator may be sprayed with a coolant exiting nozzles located in the ends of a rotor. One difficulty with this approach is, however, the fact that some of the liquid coolant sprayed on the end turns tends to find its way into the air gap between the rotor and the stator causing so called "windage" losses which reduce the efficiency of the dynamoelectric machine.
The present invention is directed to overcoming one or more of the above problems and provides an improved, positive means for cooling the end turns of the stator of a dynamoelectric machine in such a way that the coolant will not enter the rotor-stator air gap.